Networking of electronic message service systems, such as voice-mail message service systems, is known. An example thereof is disclosed in U.S. Pat. No. 4,790,003. Networking provides subscribers of the messaging service who are served by one system to send messages to and receive messages from subscribers of the service who are served by other systems.
When a service provider expands the network by adding one or more message systems thereto to serve subscribers hitherto served by another, possibly overloaded, system, or when one or more service subscribers move from a location served by one system to a location served by another system, subscribers must be "moved" from one system to the other. That is, the system which is to serve the subscribers must be made aware of the fact that it is to serve them and must be provided with information required to serve them, while the system which has been serving the subscriber must be made aware that it is no longer to do so, and other systems in the network must be appraised of the fact that the subscribers' service location within the network has changed.
The presently-used method of "moving" subscribers from one voice-mail message service system to another is cumbersome for system administrators, and moves only a minimal amount of information. Essentially, it requires deletion of each moving subscriber from the network, followed by addition of each moving subscriber to the network as a new subscriber. The administrator of the system that is presently serving the moving subscribers manually deletes information about each moving subscriber from the system, as if that subscriber had ceased subscribing to the service, and notifies the other systems to do the same. The administrator of the system that is to serve the moving subscribers then manually enters information about each moving subscriber into the system, as if he or she were adding a new subscriber, and notifies other systems of the addition. Thus, the administrator of the subscribers' new serving system must re-enter all of the information that had in the past been entered by the administrator of the subscribers' old serving system. And in the process of deleting the subscribers from the old serving system, the contents of their mailboxes, e.g., all address lists and stored messages, are lost, and the moved/deleted subscribers are deleted from address lists of the remaining subscribers on the old serving system.
A move of subscribers from one text mail system to another is often not as inconvenient: the administrator of the subscribers' new serving system manually enters information about the moving subscribers into the system to create accounts for them on the new serving system, and then manually initiates an electronic transfer of all data files pertaining to the moving subscribers from the old serving system to the new serving system, after which the administrator of the old serving system manually deletes the accounts of the moving subscribers from the old serving system. The administrators also notify other systems in the network of the move so that the other systems can update their addressing information on the moved subscribers.
While this approach does not result in the loss of the moved subscribers' data files, it still requires a substantial amount of work to be done by the system administrators in order to effect the move. Furthermore, this move mechanism is facilitated by the fact that, in many text-based mail systems, a subscriber may have the same identifier, e.g., a login, for a plurality of mailboxes one on each of a plurality of systems, and that identifier is considered by each such system to be purely local. In contrast, in other systems, such as voice-mail systems, a subscriber's identifier, e.g., an extension number, is generally universal to the whole network, and hence cannot be used to uniquely identify a plurality of mailboxes. Hence, in the above-characterized many text-based systems, information may be transferred from one mailbox to another using the same identifier, but this is not readily possible in the above-characterized other systems. Consequently, an attempt to use this approach in the context of the other systems would generally result in much cumbersome manipulation by system administrators, such as assigning temporary identifiers to mailboxes for the duration of a move, and then re-identifying the mailboxes.
A further problem exists on account of destination lists. These are lists of addresses which a subscriber keeps so that he or she may address and mail a message to those addresses by specifying the list name instead of having to specify each and every address on the list. These lists are not moved in the presently-used method of "moving" subscribers between voice-mail message service systems; hence, they are lost and must be re-created. And while such lists may not be lost in the above-described text-mail method of moving subscribers between systems, their contents are affected by moves, and hence the lists must be updated following a move in order to remain valid. But no approach to updating the lists, other than each list owner reviewing each list's contents and manually changing outdated ones, has hitherto been available.